1. Field of the Invention
The present invention relates to a dolly for use with a semi-trailer that has a compromised structure due to a load shift or an accident and can also be used in applications where semi-trailers get stuck under low bridges.
2. Description of the Prior Art
Various situations are known in which semi-trailers can not be transported in a normal fashion. For example, in some situations, the semi-trailers become structurally compromised due to a load shift or accident. In situations where there is a load shift, the structural integrity of the semi-trailer becomes compromised at an unsupported location between the front of the trailer, attached to the fifth wheel of the tractor and the rear axle, for example, as generally shown in FIG. 11. In such a situation, the load must first be removed from the trailer, typically by hand, onto another semi-trailer at the scene of the incident before the damaged semi-trailer can be moved. Unfortunately, the unloading of the damaged semi-trailer can cause additional structural damage and also create a personnel hazard since the incident can occur anywhere including a busy highway.
In yet other situations, semi-trailers are known to get stuck under low bridges. In normal situations, the height of a all bridges on a truck route is known to avoid such situations. On occasion, due to, for example, road construction, it is necessary for a truck to travel on an unplanned route. Should the semi-trailer get stuck under a low bridge, known methods for extricating the semi-trailer from the bridge. In particular, in a situation in which a semi-trailer gets stuck under a bridge, normally the load is removed, as discussed above. After the load is removed, the air is let out of all of the tires and the trailer is dragged out from under the bridge, likely causing damage to the tires and wheels and the trailer itself.
In both situations, the load must be removed from the semi-trailer first. After the load is removed, the semi-trailer must eventually be cleared from the roadway. Ideally, a dolly could be used to transport the semi-trailer without removing the load.
Various types of dollies for various applications are known in the art. These dollies are known to be useful for various purposes. Examples of such dollies are disclosed in U.S. Pat. Nos. 4,768,802; 5,727,920; 5,839,876; 6,290,248; 6,663,131; 6,843,487; 6,929,249; 7,275,345; and 7,275,753. Such dollies are also disclosed in UK Published Specification 1 563 796, all hereby incorporated by reference.
For example, U.S. Pat. Nos. 5,839,876; and 7,275,345 all relate to dollies for lifting heavy objects. In particular, U.S. Pat. No. 5,839,876 a dolly with a platform capable of lifting and rotating to enable eased transport of large, heavy objects, such as furniture and other heavy objects. The dolly includes casters for transport.
U.S. Pat. No. 7,275,345 discloses a lifting device used to support an object, such as furniture. The container has a false bottom with a hidden cavity containing a wheeled platform. The wheeled platform is exposed when the pneumatic lift bladder is filled and is height adjustable to preference and need (see column 1, lines 6-9; and column 2, lines 40-47). The lifting device includes casters for transport. Unfortunately none of the lifting devices disclosed in the above-mentioned patents are suitable for use with a semi-trailer with compromised structural integrity due to a load shift or an accident or for use in extricating a semi-trailer stuck under a low bridge.
Dollies are also known for use in transporting vehicles. For example, U.S. Pat. Nos. 5,727,920; 6,843,487; 6,929,249; 7,275,753 and UK Published Specification 1 563 796 all disclose dollies for use in transporting vehicles that have been disabled. These dollies all have lifting capability.
In particular, U.S. Pat. No. 5,727,920 discloses a configurable dolly which includes a frame with a trailer hitch on one end and an axle supporting a pair of wheels on the opposing end. The height of the frame can be adjusted as well as the distance between the wheels to enable the dolly to be configured for a variety of applications. The dolly disclosed in the '920 patent is adapted to carry an entire vehicle, such as a car, motorcycle or a boat after the dolly has been configured.
U.S. Pat. No. 6,843,487 discloses a lift structure that moveably supports an automobile with the loss of one wheel for transport. The device allows the automobile to travel along roadways or other surfaces to a repair facility. The device is secured in position to mobilize the vehicle. Attachment is achieved using gripping members that are pneumatically activated via an inflatable bladder. The lift structure disclosed in the '487 patent is adapted to provide support adjacent one wheel well 12 (FIG. 1) of a four wheeled vehicle.
U.S. Pat. No. 6,929,249 discloses a collapsible lift platform that engages a surface upon pneumatic expansion of an internal bladder. The air bladder can be filled by either an electric or mechanical (e.g. foot pump) air pump. The lift platform illustrated in FIGS. 1-5 appears to be used for lifting and supporting an area of an automobile frame, and can be stored in the vehicle trunk, as illustrated in FIG. 7. An optional embodiment, illustrated in FIG. 6, includes casters enable transport of the platform after lifting The device disclosed in FIG. 6 of the '240 patent is used to lift heavy furniture items, such as televisions.
U.S. Pat. No. 7,275,753 discloses a bi-axle dolly cradle useful for raising and towing disabled vehicles. The dolly is adapted to raise one end of a disabled vehicle. One end of the disabled vehicle is carried by the dolly which has two axles and two sets of wheels. Once the disabled vehicle is lifted onto the dolly, the other end of the disabled vehicle can be towed.
International patent GB 1,563,796 discloses an automobile retrieval system for use in applications when the damage to the vehicle makes it impossible to tow the vehicle or transport the vehicle via trailer. The system utilizes an airbag, which can be deflated to a relatively flat condition, and support members that can raise the vehicle up to approximately 1 foot. The system includes cradles for lifting a vehicle on one end by forming a cradle around the tires and lifting the cradle. Unfortunately, U.S. Pat. Nos. 5,727,920; 6,843,487; 6,929,249; 7,275,753 and UK Published Specification 1 563 796 are not suitable for semi-trailers.
U.S. Pat. Nos. 4,768,802; 6,290,248; and 6,663,131 disclose dollies which include “fifth-wheel” assemblies for towing semi trailers. The dollies disclosed in these patents have no lifting capability. Unfortunately, none of these devices can be used to lift and enable transport of a semi-trailer with structural damage.
Thus, there is a need for a device for lifting and transporting semi-trailers with compromised structural integrity. There is also a need for a device for use in extricating trailers stuck under bridges and subsequent transport of the semi-trailer, if necessary without resulting in any damage to the wheels or tires of the semi-trailer.